Wind turbine provided with a controller for adjusting active annular plane area and the operating method thereof

• US 7,425,774 B2
• Filed: 05/06/2005
• Issued: 09/16/2008
• Est. Priority Date: 01/10/2002
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Hayakawa, Koshi, Hayashi, Yoshiyuki, Shibata, Masaaki, Miyake, Hisao, Kato, Eiji, Yatomi, Yuuji, Furukawa, Toyoaki, Teramoto, Yoshinari
• Primary Examiner(s): GONZALEZ, JULIO CESAR
• Application Number:
  US11/123,130
• Publication Number:
  US 20050200134A1
• Time in Patent Office: 1,229 Days
• Field of Search: 290/55, 290/54, 290/44, 290/43, 416/1, 416/132.B, 416/11, 416/32, 416/122, 415/7, 415/2.1, 415/4.2, 415/907, 415/4.1, 603/98
• US Class Current: 290/55
• CPC Class Codes: F03D 7/0236 by changing the active surface of the wind engaging parts, e.g. reefing or furling
• CPC Class Codes: F05B 2240/3121 around an axis orthogonal to rotor rotational axis
• CPC Class Codes: F05B 2240/313 with adjustable flow intercepting area F05B2240/312 takes precedence
• CPC Class Codes: F05B 2270/32 Wind speeds
• CPC Class Codes: F05B 2270/332 Maximum loads or fatigue criteria
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y10S 415/905 Natural fluid current motor

Abstract

A wind turbine capable of varying active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With this construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Claims

1. A wind turbine with an active annular plane area control mechanism comprising a plurality of blades attached to a rotor for transmitting the wind force acting on the blades to the output shaft of the wind turbine connected to the rotor wherein each of said blade is divided into a variable length blade part and a blade body fixed to the rotor and connecting to the root of said variable length blade part, and there are provided operating conditions detectors for detecting the operating conditions of the wind turbine, a blade length controller for comparing the detected signals of the operating conditions inputted from said operating conditions detectors with predetermined permissible values of operating conditions and calculating the amounts of active annular plane area and blade length to be adjusted for optimal operation based on the result of comparisons, and a blade length adjusting mechanism for changing blade length based on the calculated blade length inputted from said blade length controller, and

wherein a blade stress detector is provided for detecting the stress occurred in the blade, and said blade length controller is composed so that the amounts of active annular plane area and blade length to be adjusted for optimal operation are calculated based on both the result of comparison of the signal of detected blade stress with a predetermined permissible value of blade stress and the result of comparisons of the detected signals of the operating conditions with predetermined values of operating conditions and the calculation result is outputted to said blade length adjusting mechanism.

2. A wind turbine with an active annular plane area control mechanism comprising a plurality of blades attached to a rotor for transmitting the wind force acting on the blades to the output shaft of the wind turbine connected to the rotor,

wherein each of said blade is divided into a variable length blade part and a blade body fixed to the rotor and connecting to the root of said variable length blade part, and there are provided operating conditions detectors for detecting the operating conditions of the wind turbine, a blade length controller for comparing the detected signals of the operating conditions inputted from said operating conditions detectors with predetermined permissible values of operating conditions and calculating the amounts of active annular plane area and blade length to be adjusted for optimal operation based on the result of comparisons, and a blade length adjusting mechanism for changing blade length based on the calculated blade length inputted from said blade length controller, and

wherein said operating condition detectors include at least one among a wind speed detector for detecting the speed of the wind acting on the wind turbine, a rotation speed detector for detecting the rotation speed of a rotating component of the wind turbine including the rotor, and a load detector for detecting the load of the wind turbine, and said blade length controller compares the signal of detected wind speed from said wind speed detector with a predetermined permissible value of wind speed, or compares the signal of detected rotation speed from said rotation speed detector with a predetermined permissible value of rotation speed, or compares the signal of detected load from said load detector with a predetermined permissible value of load, calculates the amounts of active annular plane area and blade length to be adjusted for optimal operation concerning at least one among wind speed, rotation speed, and load, and outputs the result to said blade length adjusting mechanism.

3. A wind turbine with an active annular plane area control mechanism comprising a plurality of blades attached to a rotor for transmitting the wind force acting on the blades to the output shaft of the wind turbine connected to the rotor,

wherein each of said blade is divided into a variable length blade part and a blade body fixed to the rotor and connecting to the root of said variable length blade part, and there are provided operating conditions detectors for detecting the operating conditions of the wind turbine, a blade length controller for comparing the detected signals of the operating conditions inputted from said operating conditions detectors with predetermined permissible values of operating conditions and calculating the amounts of active annular plane area and blade length to be adjusted for optimal operation based on the result of comparisons, and a blade length adjusting mechanism for changing blade length based on the calculated blade length inputted from said blade length controller, and

wherein said operating condition detectors include at least one among a wind speed detector for detecting the speed of the wind acting on the wind turbine, a rotation speed detector for detecting the rotation speed of a rotating component of the wind turbine including the rotor, and a load detector for detecting the load of the wind turbine, a blade stress detector is provided for detecting the stress occurred in the blade, and said blade length controller compares the signal of detected blade stress inputted from said blade stress detector with a predetermined permissible stress, and compares the signal of detected wind speed from said wind speed detector with a predetermined permissible value of wind speed, or compares the signal of detected rotation speed from said rotation speed detector with a predetermined permissible value of rotation speed, or compares the signal of detected load from said load detector with a predetermined permissible value of load, calculates the amounts of active annular plane area and blade length to be adjusted for optimal operation concerning at least one among wind speed, rotation speed, and load while maintaining the blade stress at or near the predetermined permissible stress, based on the result of said comparisons and outputs the result to said blade length adjusting mechanism.

4. An operating method of the wind turbine with an active annular plane area control mechanism, comprising a plurality of blades attached to a rotor for transmitting the wind force acting on the blades to the output shaft of the wind turbine connected to the rotor,

wherein the operating condition of the wind turbine is detected, the detected operating condition signals are compared with predetermined permissible values, the amounts of active annular plane area and blade length to be adjusted for optimal operation concerning the operation condition are calculated, and the blade length is changed so that active annular plane area becomes equal to said calculated value through composing such that each blade is being configured so that blade length can be changed in the total length of the blade or in a certain length from the middle up to the tip of the blade, and

wherein the blade stress is detected, the detected signal of the blade stress is compared with a predetermined permissible blade stress, the amounts of active annular plane area and blade length to be adjusted for optimal operation concerning both said operation condition and said blade stress are calculated, and the blade length is changed according to the calculation result.